Evidence for Heritable Preferences for Spawning Habitat between Two Walleye Populations

The basis of behavioral differences between populations of river‐ and lake‐spawning walleye Stizostedion vitreum was evaluated. We used fish from one population that migrates up a river to spawn on gravel bars and from another that remains in a lake to spawn on rocky shoals as broodstock to produce genetically tagged fry of each stock. Offspring from these broodstocks were introduced into a system containing both habitats. When the stocked walleyes had reached sexual maturation 3 and 4 years later, adults in reproductive condition were collected throughout the impoundment–river system. Walleyes that were the offspring of broodstock from the river‐spawning population were captured more frequently in lotic habitat well upstream from the impoundment, whereas offspring of the lake‐spawning population were found more frequently in lake habitat. This result is consistent with the hypothesis that choice of spawning habitat has a heritable component: walleyes have a genetically based response to environmental cues that guides them to spawning habitat.